The contribution of algae to freshwater dissolved organic matter: implications for UV spectroscopic analysis
The contribution of algae to freshwater dissolved organic matter: implications for UV spectroscopic analysis
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DOI：
10.1080/20442041.2017.1415032
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发表时间：
2018-01
期刊：
影响因子：
3.1
通讯作者：
Jessica L. Adams;E. Tipping;H. Feuchtmayr;H. Carter;P. Keenan
中科院分区：
文献类型：
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作者：
Jessica L. Adams;E. Tipping;H. Feuchtmayr;H. Carter;P. Keenan
摘要溶解性有机物（DOM）是淡水的重要组成部分，参与了许多关键的生态和地球化学过程，但在水处理过程中可能会出现问题。因此，对快速和可靠的监测的需求正在增长，光谱方法是潜在有用的。具有3个组件的模型-2吸收在紫外线（UV）范围内，并存在于可变浓度和第三个不吸收光，并存在于一个低的恒定浓度-以前发现产生可靠的预测溶解有机碳浓度[DOC]。然而，该模型低估了中国长江流域浅水富营养化湖泊中的[DOC]，从而提高了来自藻类的DOM可能估计不佳的可能性，这一想法得到了英国富营养化湖泊新数据的支持。我们估计的消光系数在紫外线范围内的藻类衍生DOM从已公布的数据藻类文化和新的数据从室外围隔实验中，高浓度的DOC产生的条件下，在富营养化的淡水。结果表明，与陆源DOM相比，藻类DOM的紫外吸收较弱。一个修改后的模型，其中第三个组件代表藻类衍生的DOM存在于不同的浓度，允许这样的DOM的贡献估计结合光谱数据与[DOC]通过实验室燃烧测量。在77个地表淡水样品中，藻类来源的DOC的估计浓度范围为0至8.6 mg L−1，藻类来源的DOM的比例范围为0%至100%。
Abstract Dissolved organic matter (DOM) is an important constituent of freshwater that participates in a number of key ecological and biogeochemical processes but can be problematic during water treatment. Thus, the demand for rapid and reliable monitoring is growing, and spectroscopic methods are potentially useful. A model with 3 components—2 that absorb in the ultraviolet (UV) range and are present at variable concentrations and a third that does not absorb light and is present at a low constant concentration—was previously found to yield reliable predictions of dissolved organic carbon concentration [DOC]. The model underestimated [DOC] in shallow eutrophic lakes in the Yangtze Basin, China, however, raising the possibility that DOM derived from algae might be poorly estimated, an idea supported by new data reported here for eutrophic British lakes. We estimated the extinction coefficients in the UV range of algae-derived DOM from published data on algal cultures and from new data from outdoor mesocosm experiments in which high concentrations of DOC were generated under conditions comparable to those in eutrophic freshwaters. The results demonstrate the weak UV absorbance of DOM from algae compared to DOM from terrestrial sources. A modified model, in which the third component represents algae-derived DOM present at variable concentrations, allowed contributions of such DOM to be estimated by combining the spectroscopic data with [DOC] measured by laboratory combustion. Estimated concentrations of algae-derived DOC in 77 surface freshwater samples ranged from 0 to 8.6 mg L−1, and the fraction of algae-derived DOM ranged from 0% to 100%.